x509: update auth-key-id in precert too
x509: update auth-key-id in precert too

daviddrysdale/certificate-transparency-go,daviddrysdale/certificate-transparency-go,RJPercival/certificate-transparency-go,RJPercival/certificate-transparency-go,google/certificate-transparency-go,google/certificate-transparency-go,RJPercival/certificate-transparency-go,google/certificate-transparency-go,daviddrysdale/certificate-transparency-go